Urinary Incontinence in the Elderly : Pathogenesis and Management

CLINICAL MEDICINE Urinary Incontinence in the Elderly : Pathogenesis and Management Gayathri Bhagwath* Abstract With increasing life spans, the average age of our elderly population is increasing. Therefore, it is important for physicians to understand the physiology of ageing and learn the management of special problems arising in this age group. Urinary incontinence is a problem that often fails to get mentioned privately in the physician s office or publicly in our society. This article aims at improving awareness and providing a brief overview regarding the management of this problem. Keywords Urinary Incontinence, Geriatrics. Urinary incontinence or the involuntary loss of urine is a very common problem facing the elderly population. It is often considered a normal part of ageing and seldom mentioned by patients, especially women, who perceive it to be very embarrassing. Affected persons may isolate themselves from society leading to social anxiety and emotional problems such as depression. Urinary incontinence can also lead to medical problems such as local skin irritation, rashes, and urinary infections. In the debilitated and bed bound patients it can lead to pressure ulcers which can increase the risk of localised and systemic infections including osteomyelitis and sepsis. Therefore it is important for physicians to understand the mechanisms of urinary incontinence in the elderly and learn about their management. Normal bladder physiology 1 The urinary bladder can be described as a hollow bag made up of smooth muscle fibres of the detrusor muscle. It stores urine, which is excreted to the exterior via the urethra. Anatomically, the urethra makes an angle with the body of the bladder, which is physiologically important to maintain continence. The urethra * Practitioner : St. Louis, Missouri 1477 Mississauga Valley Blvd, # 204 Mississauga, Ontario L5A 3Y4, Canada. is surrounded by smooth muscle fibres (internal sphincter) which are under autonomic control and the external sphincter, which is under voluntary control. Stretch receptors present in the detrusor muscle get stimulated when the bladder gets distended raising the intravesicular pressure, leading to stimulation of the parasympathetic nerves to the bladder (S 3 ). Parasympathetic stimulation leads to contraction of the detrusor muscle and relaxation of the urethra resulting in voiding. The sympathetic innervation of the bladder (from T 11 to L 2 ) has the opposite action of relaxing the bladder and contracting the urethra. Voluntary control of micturition occurs at the neurons in the second frontal gyrus with their associated descending pathways. The pathways help connect it to hypothalamic and pontine centres that facilitate micturition. The volitional mechanisms inhibit voiding till the person desires normally till the availability of appropriate opportunity and facility. The muscles of the pelvic floor also facilitate micturition by their relaxation and are controlled by the motor cells at the S 3 level in the spinal cord. Micturition occurs when there is relaxation of the voluntary control, the pelvic floor muscles, the external sphincter, and contraction of the detrusor. As the bladder contracts the

intravesicular pressure rises which forces the urine out with the aid of gravity. An unobstructed urethra leads to uncomplicated voiding. Pathogenesis of urinary incontinence 1-5 Incontinence can occur when there is a disturbance or malfunctioning in any of the components of micturition. Anatomical causes 1. Detrusor hyperactivity leads to involuntary loss of urine as soon as a sensation of bladder fullness is felt. A sense of urgency to urinate results, leading to the term urge incontinence. It may be isolated or due to certain associated factors. a) Infection or inflammation of the urinary tract can make the stretch receptors in the bladder oversensitive and lead to premature parasympathetic mediated contraction. b) Impaired bladder contractility leads to inefficient emptying and an overactive bladder. (detrusor hyperactivity with impaired contractility or DHIC) 6. c) Central nervous system (CNS) disorders leading to damage in the second frontal gyrus and its pathways thereby leading to loss of voluntary control over urination. Examples include tumours, meningiomas, and aneurysms of the frontal lobe, normal pressure hydrocephalus, Parkinson s disease, multisystem atrophy. 2. Detrusor laxity leads to large atonic bladders, which cannot generate sufficient intravesicular pressure that is required to initiate urination. The bladder is hyperdistended and this causes overflow incontinence. It s occurrence in isolation can be seen with diabetes mellitus, sacral spinal cord injury, pelvic malignancies or surgery, and multiple sclerosis all of which damage the nerve supply to the bladder. It can occur in combination with detrusor hyperactivity (DHIC) as mentioned above. 3. Outflow tract obstruction results in increased intravesicular pressure, overdistended bladder, and overflow incontinence. Causes include prostatic hypertrophy (either benign or malignant), urethral stricture, and cystocoele. 4. Loss of bladder urethral angle from faecal impaction, cystocoele, and uterine prolapse. 5. Pelvic floor musculature laxity results in hypermobility of bladder base and adjoining urethra. Causes include previous local surgery, trauma due to childbirth. Any increase in intra-abdominal pressure caused by coughing, sneezing, or laughing can lead to stress incontinence. 6. Detrusor sphincter dyssynergia occurs due to suprasacral spinal cord lesions from trauma, tumour, or multiple sclerosis. In these patients bladder distension is felt as sweating, pallor, hypertension, and flexor spasms leading to a work-up for phaeochromocytoma. Although uncommon in everyday practice, physicians caring for patients with spinal cord injury should be aware of this problem. Functional causes Psychological, physical, and environmental causes may prevent an elderly person from voiding urine normally. Delirium, dementia, and psychosis can interfere with a patient s ability to understand the sensation of bladder fullness and find the toilet/commode. A severely depressed patient may lack the motivation to find a suitable place for voiding. Delirium is a common cause of incontinence in hospitalised patients. Frailty, injury, illness, or surgery can also render many elderly patients immobile. Lack of easy access to toilets or prompt help are environmental causes of incontinence. Journal, Indian Academy of Clinical Medicine Vol. 2, No. 4 October-December 2001 271

Increased production of urine Increased urine production is associated with diabetes mellitus, hypercalcaemia, congestive heart failure (CHF), and peripheral venous congestion. Certain drugs can also achieve this effect as discussed later. Even though there is no pathology in the urinary tract, these patients may be overwhelmed by the increased number of visits to the toilet leading to incontinence. Drugs Drugs are a major cause of incontinence in the elderly and can produce incontinence through any of the mechanisms mentioned above. Anticholinergics, antipsychotics, opioids, antidepressants, and calcium channel blockers can cause urinary retention and overflow incontinence. Diuretics and alcohol can cause polyuria. Angiotensin converting enzyme inhibitors induce cough and stress incontinence. Many of these drugs can also cause sedation and/or delirium leading to functional incontinence. Evaluation The aim of evaluating urinary incontinence is two fold : 1. To diagnose and treat reversible causes. 2. To improve the quality of life and prevent complications in patients with established causes. It must be noted that more than one cause of incontinence exists in many patients. Evaluation of this problem in hospitalised patients is easier when a team approach is chosen. History As most patients hesitate to mention problems due to urinary incontinence, physicians should routinely ask all elderly or high-risk patients whether they suffer from any such problem. A sympathetic but proactive approach will put the patient at ease and prevent further morbidity. Duration, pattern, and frequency of urination along with the inducing factors should be enquired. A voiding record maintained over 2-3 days is of great help to physicians. In an outpatient setting it can be done by the patient or caretaker. In a hospital, the nursing and ancillary staff can be of great help in obtaining this information. Associated symptoms such as fever, pain, haematuria, and constipation should be noted. A detailed past medical, surgical, and obstetrical history should be obtained. Medications should be reviewed. Physical examination A complete physical examination inclusive of the nervous system and a relevant mental examination must be performed. In men and women attention should be paid to prostate and pelvic examinations respectively. A digital rectal examination to evaluate sphincter tone and exclude faecal impaction is required in both sexes. The cough test to provoke stress incontinence should be done in an upright (female) patient and is particularly useful when the patient has at least 200 cc of urine in the bladder 2. If leakage of urine is immediate, weak pelvic floor musculature is the cause. If urine leaks a while after coughing, it s due to involuntary bladder contraction induced by the cough 3. Urine analysis of a clean catch mid-stream sample should be done on all patients complaining of incontinence. The post-void bladder residual urine volume (PVR) can be checked after micturition. If greater than 400 cc, it is suggestive of DHIC in women and either bladder outlet obstruction or hypoactive detrusor in men 4. PVR can also be measured by bladder ultrasound. Involuntary bladder contractions can be studied using cystometry and help in diagnosing hyperactive bladder. Complex urodynamic testing can be done to evaluate detrusor and urethral sphincter function, but their description is beyond the scope of this article. Complex testing will need specialist referral. 272 Journal, Indian Academy of Clinical Medicine Vol. 2, No. 4 October-December 2001

Table I : Clinical features of common causes of incontinence 1-4 Cause of incontinence Detrusor hyperactivity (urge incontinence) Detrusor underactivity Bladder outlet obstruction Faecal impaction Cystocoele, Uterine prolapse Pelvic floor musculature laxity (stress incontinence) Functional incompetence Increased urine production Drug-induced Features Intense, uncontrollable urge to urinate Usually large volume of urine leaks out Absence of stress factors Obstructive features may co-exist PVR normal but high in DHIC Most common cause of geriatric incontinence Dribbling of urine (small amounts) Urinary urgency, frequency, nocturia Urinary retention PVR high Uncommon Dribbling of urine (small amounts) after voiding Urinary urgency, frequency, hesitancy Nocturia Urinary retention PVR high Second common cause in men History of constipation Faecal incontinence Relieved with disimpaction Observed on pelvic examination Small amounts of urine loss with coughing, sneezing, laughing Absent on lying down PVR low Second common cause in women Presence of physical, mental impairment Unavailability of toilet facilities/assistance Features of CHF, ankle oedema or associated diseases. Single/multiple causative medications on review Table II : Treatment (Compiled from references 3,7, and 8). Cause Treatment Remarks Detrusor hyperactivity Behavioral therapy with voiding at Upto 50% effective. (Investigate any case regular intervals 7 associated with sterile Prompted voiding in uncooperative For dementia patients haematuria or pain for patients bladder stones / tumour) If above not helpful Urethral obstruction to be Oxybutynin 2.5 to 5 mg three to four Prefer low doses. All four medications ruled out prior to bladder times/day can cause urinary retention due to Journal, Indian Academy of Clinical Medicine Vol. 2, No. 4 October-December 2001 273

relaxant use to avoid Terodiline 1 to 2 mg twice daily anticholinergic side effects. urinary retention Imipramine 25-100 mg at bedtime Doxepin 25-100 mg at bedtime Imipramine helps concurrent depression. Due to urinary infection Antibiotics Due to atrophic vaginitis local/systemic oestrogen With oral oestrogen add progesterone and urethritis in a woman with uterus. DHIC Behavioral therapy Detrusor underactivity Double voiding All measures reduce PVR Application of suprapubic pressure during voiding Intermittent or long term catheterisation Bladder-outlet obstruction Treatment of enlarged prostate with surgery or medication Terazosin 1 to 5 mg every night Tamsulosin 0.4 mg every day Doxazosin 1 to 4 mg every day Finasteride 5 mg everyday Intermittent catheterisation Stress incontinence Pelvic muscle (Kegel exercises) Biofeedback Oestrogen Vaginal pessary Surgical repair of pelvic floor, prolapse, or bladder neck suspension Functional incontinence Treat underlying cause if possible Easy access to commode with help. Increased urine production Treat underlying cause Drug-induced Avoid/change medication if possible Reduce dosage or change time of administration Behavioral therapy refers to bladder re-training. A regular timetable is set for voiding depending on the patient s ability to hold urination. As the patient improves, voiding intervals are increased. This method helps patients with both detrusor overand under-activity. In addition to the above, use of a protective pad or undergarment must be practiced to avoid social and medical problems. Management of incontinence due to neurological problems may not always be reversible but is an integral part of the patient s rehabilitation efforts. In patients with urinary catheters, asymptomatic bacteriuria need not be treated. Summary Urinary incontinence can be a debilitating problem for our elderly patients either in the community or in an in-patient setting. Any effort to cure or improve this problem has benefits that reach far beyond the clinical realm. Investigations and treatments must be chosen carefully to best help patients (beneficence) and avoid unnecessary harm (non-maleficence) 9. Physicians should be aware of the iatrogenic causes of incontinence and work towards preventing them. Medications used should be reviewed for drug interactions and side effects and used in lower doses, if possible. Catheters inserted in the acute care setting must be properly managed in a sterile manner and discontinued as soon as possible. With proper management improvement or restoration of urinary continence can significantly improve the quality of life in geriatric patients. 274 Journal, Indian Academy of Clinical Medicine Vol. 2, No. 4 October-December 2001

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